The fuel adjusting member of a compression ignition engine is normally controlled by a speed sensitive governor which adjusts the position of the fuel adjusting member in response to changing load conditions which cause a change in the engine speed. An air fuel ration control is also used on some engines in combination with a governor to coordinate the movement of the fuel adjusting member and thus the amount of fuel with the amount of air available in the inlet manifold to keep the exhaust smoke to a minimum. Although this combination of components has successfully reduced the emission of exhaust smoke under most conditions, it has been found that controlling the torque rise by decreasing the amount of fuel delivered to the combustion chambers when the engine speed decreases from its rated speed to its peak torque speed under the influence of a load will reduce the amount of exhaust smoke during that period of operation. However, one of the problems has been that heretofore it has been necessary to redesign the governor for achieving this feature rather than providing an add-on component to utilize the capability of an existing component. For example, it has been found that reducing the air pressure at pressure at the air fuel ratio control under certain conditions causes it to move the fuel adjusting member toward a reduced fuel setting. However, a speed sensitive pressure regulator has not been available heretofore for reducing the air pressure to changes in engine speed.